This invention relates to machine tools with automatic tool changers and more specifically, to a machine tool having an internally mounted automatic tool changer.
The advent of automatic tool changers on machine tools has greatly improved producivity by allowing for complete automation of machine operation. Exchange of a cutting tool held by the machine spindle with a new tool, which previously required the efforts of a human operator, can now be effectuated automatically by the machine, thereby permitting unmanned machine tool operation for long periods of time. The only time it may be necessary for a human operator to intervene during machine operation is when a tool must be replaced, due either to wear or breakage.
Present day automatic tool changing machine tools include a tool storage magazine located either above, behind, or to one side of the machine tool spindle.
During a tool change cycle, the tool storage magazine is rotated to place a selected one of the tool holding sockets in the tool storage magazine in a ready position within the reach of a tool transfer arm. The tool transfer arm, actuated under the command of the machine tool control system, transfers the tool at the ready position to the spindle and returns the tool formerly held in the spindle to the tool storage magazine at the ready position. Subsequent rotation of the tool storage magazine places a new tool in the ready position to facilitate another tool exchange.
Typically, the tool storage magazine carries a large number of cutting tools, each weighing between 15 and 20 Kg. (30 to 40 lbs.). Because of the weight of the tools, as well as their size, mounting of the tool storage magazine above, behind, or to the side of the spindle requires considerable modification of conventional machine tool designs to avoid interference with machine tool operations. Further, mounting of the tool storage magazine above, below, or to the side of the spindle incurs the disadvantage that mounting of the tool storage magazine in this manner is likely to expose the cutting tools carried therein to metal chips and coolants disseminated during machining operations. Excessive exposure to such chips and coolant during machining operations can lead to not only tool damage but also to damage to the tool storage drum itself.
In contrast, the present invention concerns a machine tool having a tool storage magazine slidably mounted within the machine tool upright which permits the tool storage magazine to be retracted into the recess and away from the spindle during machining operations thereby virtually eliminating interference with machine operation, as well as shielding the cutting tools carried thereon from disseminated coolant and chips.
It is an object of the present invention to provide a machine tool having an internally mounted automatic tool changer retractable into the machine tool upright which virtually eliminates interference between the tool changer and the machine tool during machining operations.
It is another object of the present invention to provide a machine tool having an internally mounted automatic tool changer retractable into the machine tool upright to shield cutting tools from metal coolant and chips disseminated during machining operations.
It is yet another object of the present invention to provide a machine tool having an internally mounted automatic tool changer retractable into the machine tool upright having reduced complexity and cost in comparison with other present day automatic tool changers.